The subject invention is a fastening device for aiding in the process of securing sheets of rubber roofing to the upper surface of a roof. In this regard, roofing sheets made of rubber material are now used more widely for roof coverings because of the durability factor.
The general approach is to place over the upper roof surface rubber roof sheets so that they encompass the entire upper roof surface as a complete and secure roof covering. In many applications, strategically placed bonding plates are affixed over the top of the rubber roof sheets to secure the rubber roof sheets in a flush manner to the upper roof surface. A usual arrangement in using such fastening or bonding plates is a series of evenly-spaced rows and columns of such plates, regularly and symmetrically spaced as seen from an upper elevational view. Bonding plates function to securely hold the rubber roofing sheets in place with the aid of a fastening device such as a longitudinally extending screw-like or nail-like member forcibly thrust downwardly through the horizontally disposed bonding plate through the rubber roofing material, and into the roof deck or fixed roof structure. Thus, the present practice, as stated, is to affix the bonding plates over the upper roof surface, using nails or screws in order to firmly adhere the bonding plate firmly against the upper surface of the roofing sheets.
One of the predominant problems encountered with the use of nails or screws in fastening such bonding plates is that when they are inserted into the roof deck, they generally cause distortion damage in the wood or other roof material immediately around the screw or nail. Such distortion damage usually leaves gaps or spaces adjacent the screw or nails. This, in turn, causes weakness in the roof structure and also yields a potential source of roof leaks through the nail openings. Yet another problem that is encountered in this regard is that at times when the nail or screw-like member is lodged through the roof structure at an angle from the vertical, the hole in the roof becomes uneven and the top plate does not rest securely and flush against the roof surface. As a result, air and water may penetrate through the roof at this juncture. This invention is therefore directed to overcome these problems and the following objects are directed accordingly.